JP2989459B2 - Spectrometer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light source for irradiating a measuring beam to which a sample to be measured can move back and forth, and a measuring light beam transmitted through or reflected from the measuring portion. The present invention relates to a spectroscopic analyzer for analyzing the components of a sample, comprising a spectroscopic means for splitting light and an array-type light receiving element for receiving the split light beam for measurement.

[0002]

2. Description of the Related Art Conventionally, in an array type light receiving element provided in this type of spectroscopic analyzer, the charge accumulation time is fixed, and the component analysis of rice, wheat, fruit, etc. can be performed with a predetermined charge accumulation time. Was doing it.

[0003]

In the apparatus having such a configuration, when rice such as brown rice or white rice is to be subjected to the component analysis, the moisture content thereof is relatively constant (substantially 13%).
１６16%), so that there is no large change in absorbance for each sample, and it is possible to obtain a light amount appropriately distributed within the measurement range of the array-type light receiving element when spectrally separated.
As a result, a reliable analysis result can be obtained.
However, when the analysis target is, for example, wheat, the water content greatly varies from 10 to 40% depending on the sample.
Therefore, the variation in the amount of transmitted light is very large depending on the sample (differs by one digit or more), and saturation or insufficient light amount occurs in the array type light receiving element. That is, as shown in FIG. 5B showing the relationship between the wavelength and the output value of the array-type element, if the accumulation time is fixed, the amount of received light (output voltage value) is too low (in FIG. In the following processing, appropriate data for obtaining a reliable result cannot be obtained in the subsequent processing because the received light amount (output voltage value) is too high (the state indicated by A in the figure). Therefore, for example, in order to cope with a state where the amount of received light is excessive, if a wide measurement range (maximum light amount value) is set to cover all the ranges so that all the wheat can be measured, the resolution is deteriorated. On the other hand, if the measurement range is set small, it is not possible to cope with the case where the transmitted light amount is large. In FIG. 5, the voltage added in parentheses to each output curve is the maximum output value.

Accordingly, it is an object of the present invention to provide a spectrometer capable of performing an appropriate measurement irrespective of a change in water content.

[0005]

According to a first aspect of the present invention, there is provided a spectroscopic analyzer, wherein wheat as a sample is analyzed and the charge storage time of the array type light receiving element is changeable. by increasing or decreasing control the time, with the charge accumulation time adjusting means to fall within a preset predetermined output range of the output from the array-type light receiving element, the charge storage time
As the standard accumulation time for dry wheat and for raw wheat
Short accumulation time and long accumulation time for overdried wheat
The charge accumulation time adjustment means sets the charge accumulation time
The switching control is performed to one of the three accumulation times.
And there. Characteristic configuration of the spectroscopic analyzer according to claim 2
Is to analyze wheat as a sample,
The charge accumulation time of the array-type photo detector can be changed.
Control the charge accumulation time to increase or decrease
Charge that keeps these outputs within a predetermined output range
An accumulation time adjusting means is provided so that the light source
It has a large amount of light, and the amount of light is
An array-type light receiving element at a specific wavelength
The upper limit output set value and the lower limit output set value of the
The charge accumulation time adjusting means is an element element for a specific wavelength.
Charge storage time when the slave output is greater than the upper limit output set value
Is controlled to be short, and charge
This is to control the product time longer.

[0006]

In the spectroscopic analyzer according to the first aspect, the charge accumulation time of the array type light receiving element is variably configured, and a charge accumulation time adjusting means is provided so that the output from the array type light receiving element is within a predetermined output range. Since the element is adjusted to be within the range, the element does not saturate or the output is too small, so that the output from the array-type light receiving element does not sufficiently represent the light absorption state of the sample. More specifically, the output distribution from the array-type light receiving element is changed according to the amount of transmitted light as shown in FIG. 5A (the output value distribution with respect to wavelength becomes a value near the upper limit output set value or less at the peak position. At the same time, a constant distribution state is shown within the measurement range). Therefore, even when wheat whose moisture content varies greatly as a component analysis target is analyzed, analysis can be performed in an appropriate data income state, and highly reliable analysis can be performed. Further, in the spectroscopic analyzer according to claim 1,
Standard accumulation time for dry wheat as charge accumulation time,
Short side accumulation time for raw wheat and long for overdried wheat
Side storage times are set, and the charge storage time
The load accumulation time is switched to one of the three accumulation times.
Because it is assumed that the representative moisture corresponding to the moisture content of wheat
Switching operation of the accumulation time with a simple configuration using three accumulation times
This makes it possible to analyze between wheats with different moisture content.
We can deal with it, for example, differences in wheat varieties,
Is the inside of wheat, such as powdery or glassy
Even if there are differences in properties, it can be easily handled. Claim 2
In the spectrometer according to the first aspect, as in the first aspect,
The following operation is achieved. That is, the charge storage of the array type light receiving element
The product time can be made variable and the charge accumulation time can be adjusted.
A stage is provided to control the output from the array
To adjust so that it fits within the enclosure, the element may saturate,
The output from the array type photodetector is too small
Can not represent the absorbance state of the sample well
Never. More specifically, according to the amount of transmitted light,
Fig. 5 (a) shows the output distribution from the array type light receiving element.
(The output value distribution with respect to wavelength
When the value becomes close to or less than the upper limit output set value,
Can be set to indicate a certain the distribution state in the Nji)
Becomes Therefore, the moisture content of the target for component analysis greatly changes.
Appropriate data even when targeting wheat
Analytical, reliable, income status
An analysis can be performed. Further, according to claim 2
In a spectrometer, the light source is
It has a large amount of light, and the amount of light is
An array-type light receiving element at a specific wavelength
The upper limit output set value and the lower limit output set value of the
The charge accumulation time adjusting means is an element element for a specific wavelength.
Charge storage time when the slave output is greater than the upper limit output set value
Is controlled to be short, and charge
Since the product time is controlled for a long time,
The light intensity of the measurement light beam is between the limit values at a specific wavelength.
(Between upper limit output set value and lower limit output set value)
An appropriate charge accumulation time can be quickly set.

[0007]

As described above, a spectrometer capable of performing an appropriate measurement irrespective of a change in water content can be obtained.

[0008]

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A spectroscopic analyzer using wheat (variety Chihoku) as a sample S, which is an embodiment of the spectroscopic analyzer according to the present invention, will be described below.

As shown in FIG. 1, the spectroscopic analyzer includes a light source 1, a first optical system 2 for shaping a measurement light beam from the light source 1, and a sample to which the measurement light beam is irradiated in a sample measurement state. A holding unit 3, a second optical system 4 for collecting the measurement light beam transmitted through the sample S held by the sample holding unit 3, and a measurement light beam collected by the second optical system 4. The spectroscopic analysis unit 5 for performing spectroscopic analysis is arranged along the optical axis P.

The light source 1 is constituted by a tungsten-halogen lamp. The first optical system 2 includes a lens 2a for shaping a light beam heading toward the sample holding unit 3 into a parallel light beam. Further, the first optical system 2 is provided between the light source 1 and the spectral analysis unit 5 on the optical axis P of the measurement light beam. (In the embodiment, the spectral analysis unit 5 side of the sample holding unit 3) is provided with a switching unit 200 for switching this light beam to a predetermined state. The switching means 200 includes a rotating disk 20 that rotates around an axis, and as shown in FIG. 2, a wavelength calibrating unit 20a having a calibration filter that transmits a measurement light beam and converts it into a calibration light beam.
A reference portion 20b that transmits the measurement light beam to make it a reference light beam, a dark current measurement shielding portion 20c that blocks the measurement light beam, and a cutout portion 20d that passes the measurement light beam as it is. Prepare for the direction. The state of the transmitted light is switched to each state by the rotation of the rotating disk 20 around the rotation axis 21. As shown in FIG. 3, the above-mentioned calibration light flux is a light flux having a peak at a pair of specific wavelengths (λ ₁ λ ₂ ). Based on the positional relationship between a pair of corresponding elements of the array-type light receiving element 7 to receive light, correspondence is established between each element constituting the array-type light receiving element and the wavelength of light received by each element (calibration is performed). Can do). On the other hand, the reference light beam is a light beam whose standard light amount has been reduced by a neutral density filter or the like provided in the reference portion 20b, and the reference portion 20b forming the reference light beam has a configuration having a standard absorbance. Has become.

The sample holding unit 3 is constituted by a quartz glass container 3a, in which wheat as a sample S is stored. As shown in the figure, the container 3a has a retracting means 30a for a measuring section 30 through which the optical axis P of the measuring light beam passes, in a state crossing the optical axis P and a state separating from the optical axis P. It is configured to be able to move in and out freely. The second optical system 4 includes a condenser lens 4a for condensing the light beam transmitted through the sample S at the position of the entrance hole 5a of the spectral analyzer 5, and a dark box 4b for preventing harmful light from entering the optical path. It consists of.

The spectroscopic analysis unit 5 includes a dark box 5b adjacent to the second optical system 4, and within the dark box 5b, a concave diffraction grating 6 serving as a spectral unit for spectrally reflecting an incident light beam;
An array type light receiving element 7 for detecting the intensity of the light beam for each wavelength that has been spectrally reflected is provided. Further, between the entrance hole 5a and the concave diffraction grating 6 in the measurement optical path in the dark box 5b, a reflecting mirror 8 for reflecting the incident light beam from the entrance hole 5a toward the concave diffraction grating 6 is provided. It is provided. That is, the spectroscopic analysis unit 5 is a polychromator type spectrometer.

The array type light receiving element 7 is fixedly installed on a light receiving element fixing portion 9 provided in the dark box 5b on the optical path for dispersing a light beam by the concave diffraction grating 6, and is made of silicon (S).
i) or a lead sulfide (PbS) or germanium (Ge) sensor.

The detection signal from the array type light receiving element 7 is sent to a processing means 70, and is processed by the processing means 70. As shown in the following operation order, the spectrum of the absorbance, the second derivative of this spectrum, etc. Is required. Then, the component amounts such as the moisture value, the protein value, and the amylose value of the sample S are obtained from the spectrum related information in accordance with the calibration formula stored in the processing means 70. Further, the link between the switching means 200 and the processing means 70 is adopted by the control means 10.

Now, the sample S
Is placed in the measuring section 30 to measure the sample, the transmitted light amount level of the sample S is trially measured, and the accumulation time of the array type light receiving element 7 is automatically (switched, changed) by three.
A charge storage time adjusting means 71 for switching between stages is provided. That is, the charge accumulation time adjusting means 71 previously stores the standard accumulation time for dry wheat (specifically, 400 ms), the short accumulation time for raw wheat (specifically, 200 ms), and the charge accumulation time for over-dried wheat. The long accumulation time (specifically, 600 ms) is registered. On the other hand, as shown in FIG. 5, the light source 1 has a maximum light amount has, and specific wavelength lambda characteristic quantity is decreased at a wavelength away from the _c in lambda _c (the wavelength of maximum light amount) specific wavelength, this array-type upper output setting value Vmax and the lower limit power setting value Vmin of the light receiving element is set in advance at a particular wavelength lambda _c, the charge accumulation time in the case where the element output element corresponding to a particular wavelength lambda _c is larger than the upper limit power setting value Vmax Is controlled to be short (specifically, 400 m for trial measurement).
s and the output of the element corresponding to the specific wavelength λ _c exceeds the upper limit output set value Vmax, 20
Switch to 0ms), the said lower output setting value for controlling a longer charge accumulation time if Vmin is smaller than (specifically, is set to 400ms if the trial measurement, the elements corresponding to the specific wavelength lambda _c If the output is smaller than the lower limit output set value Vmin, switch to 600 ms)
It is configured as follows. Therefore, this adjusting means 71
In the state where the transmitted light amount level (output value from the element) is indicated by A in FIG. 5 (b) (there are many wavelength ranges where the output value is the maximum value of the element output), the element accumulation time is selected to be short. On the other hand, in the state indicated by C in FIG. 5B (the state where there are many wavelength ranges where the output value is considerably low), the operation is performed so as to select a longer element storage time. By making such a selection, it is possible to eliminate the incorrectly measured wavelength range (wavelength range where the element is in a saturated state or the output value is too small) of the measured value level (output value) and perform the measurement. The range can be narrowed, and the resolution can be improved. More specifically, the charge accumulation time of the conventional fixed type is 400 ms, and the device output needs a range capable of measuring from 0 to 8 V according to the change in the moisture content. 5A, the charge accumulation time is 200 ms in the A state, 400 ms in the B state, and 600 ms in the C state shown in FIG.
Can be switched to the three states of
V can be measured.

The operation sequence of the spectroscopic analyzer of the present invention will be described below in a bulleted form according to FIG. The data processing is performed by the processing means 70 linked with the switching means 200 described above. 1 Start of Measurement (Process of Collecting Wavelength Calibration Data) This state is the state shown in FIG. 4A, in which the container 3a is held in a retired state with respect to the measurement unit 30. Nor. On the other hand, the rotating disk 20 assumes a state in which the wavelength calibrating unit 20a, which is the origin state, is positioned on the optical axis P. When the measurement light beam is irradiated, the light beam transmitted through the wavelength calibration unit 20a is converted into a calibration light beam having a peak at a pair of specific wavelengths (λ ₁ λ ₂ ). The light is received by the light receiving element 7, and the correspondence between each element and the wavelength is obtained. This is performed for each sample measurement.

2-1 Reference Information Collection Process This state is the state shown in FIG. 4B, and the container 3a is held in a state of being retracted with respect to the measurement unit 30 as in the above-described process. There is nothing in the measurement unit 30. on the other hand,
The rotating disk 20 is rotated so that the reference portion 20b has the optical axis P.
Take the state located above. Then, when the measurement light beam is irradiated, the light beam transmitted through the reference portion 20b passes through a reference (ground glass or the like) in a measurement state (temperature) to be a reference light beam, and is referred to as reference information Rd. Is obtained. 2-2 Dark Information Collection Process at Reference Information Collection This state is the state shown in FIG. 4C, in which the rotating disk 20 rotates and the dark current measurement shield 20c is positioned on the optical axis. Is done. Therefore, in this state, no light enters the array type light receiving element 7, and reference dark information Dr in the measurement state is obtained. On the other hand, the container 3a in which the sample is filled into the container 3a is moved to the measuring unit 30. Here, in the collection of the reference information Rd and the dark information Dr at the time of collection of the reference information, the charge accumulation time is the standard accumulation time described above (specifically, 400 m
s). The charge accumulation time when collecting reference-related information in this manner is referred to as a first charge accumulation time.

3. Wavelength Calibration Processing Step After the above steps are completed, wavelength calibration (processing on software) is performed in the processing means 70.

4-1 Sample Data Collection Process This state is the state shown in FIG. 4D, in which the container 3a is located in the measuring section 30 and the measuring light beam is transmitted through the sample. Become. On the other hand, the rotating disk 20 is rotated so that the notch 20d is positioned on the optical axis P. Therefore, the sample information Sd is irradiated by the measurement light beam and receiving the transmitted light transmitted through the sample.
Can be obtained. In this process, the above-mentioned accumulation time adjusting means 71 is operated to test-measure the transmitted light level of the sample and to set the accumulation time of the array type light receiving element 7 in one of the states shown in FIG. The state is automatically switched to three stages. Referring to further case of wheat specifically different moisture content, the 200ms storage time indicated in the case moisture content of more than 25% A state (element output of a particular wavelength lambda _c is equal to or greater than V _max), When the moisture content is 15 to 25%, the state B (specific wavelength λ
4 the element output _c is shown by entering) between the V _max and V _min
The storage time of 00ms, more (the element output of a particular wavelength lambda _c is less V _min) approximately C state in the case of 15% or less
Is switched to the accumulation time of 600 ms shown in FIG.
The measurement state as shown in FIG. Here, the criterion of switching is the upper limit output set value V _max and the lower limit power setting value V _min, which is set in advance, the moisture content of the sample S, (or powdery or glassy) internal condition, due to variety etc. is not. By adopting such a configuration, the measurement accuracy is also improved by improving the resolution in the measurement (the resolution is doubled when the measurement range is halved). 4-2 Dark Information Collection Process at the Time of Sample Information Collection This state is the state shown in FIG. 4C, in which the rotating disk 20 rotates and the dark current measurement shield 20c is positioned on the optical axis. Is done. Accordingly, in this state, no light enters the array type light receiving element 7, and the sample dark information Ds in the measurement state is obtained. Here, in the collection of the sample information Sd and the dark information Ds at the time of collection of the sample information, the charge storage time is set as the charge storage time (specifically, the three types of charge storage times) set in the above-described trial measurement. Either). The charge accumulation time when collecting sample-related information in this manner is referred to as a second charge accumulation time.

5. Absorbance and other spectral data calculation process From the sample information Sd, reference information Rd, sample dark information Ds, and reference dark information Dr obtained in the above process, an absorbance d is obtained according to the following equation. . Absorbance d = log ((Rd-Dr) / (Sd-D
s)) Further, the second derivative in the wavelength region of the absorbance spectrum is obtained from the absorbance spectrum. And
Using the second derivative of the spectrum at a plurality of set wavelengths, the component value of each component (moisture value, protein value, amylo maximum viscosity value, etc.) in the sample is determined. In this calculation, in the spectroscopic analyzer of the present application, since the wavelength calibration, the reference measurement, and the dark output measurement are performed for each measurement, the component amount can be accurately estimated. Therefore, the reliability of the measurement is improved.

[Alternative Embodiment] (a) In the above embodiment, three accumulation times are prepared. However, the number can be set arbitrarily and the number of charge accumulation time adjusting means can be adjusted. The charge accumulation time may be sequentially increased or decreased in set units in accordance with the determination of the light quantity shortage or excess. (B) In the above embodiment, the light quantity is determined to be insufficient or excessive based on the received light quantity (element output) of the specific wavelength indicating the maximum light quantity of the light source. It is also possible to determine whether the amount of light is insufficient or excessive, or to integrate the output values over the entire wavelength range and make a determination from this integrated value. (C) In the above embodiment, a tungsten-halogen lamp is used as the light source 1. However, the present invention is not limited to this, and can be set as appropriate according to the sample S and the measurement purpose. A heat radiator (black body furnace) as a light source 1 having a light source, a light source 1 such as a mercury lamp or a Ne discharge tube, a laser emitting monochromatic light for measuring Raman scattering, or the like can be used. Can also be changed as appropriate. (D) Further, in the above embodiment, the sample S
Although the analysis was performed using the measurement light beam transmitted through the light source, this may be used as reflected light.

(E) In the above embodiment, the switching means is provided with a rotating disk, and each step is performed by rotating the rotating disk. However, as shown in FIG. Reference numeral 22 designates each part (wavelength calibration unit 20a, reference unit 20b, dark current measurement shield 120c, notch unit 20c).
d) may be provided, and the state of the measurement light beam may be determined by moving the member 22 with respect to the optical axis P. (F) In the above-described embodiment, the example of the wheat flour was shown as the analysis target. However, the configuration of the present application works effectively for grains (especially wheat) whose moisture content changes greatly.

In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the configuration shown in the attached drawings.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a spectroscopic analyzer.

FIG. 2 is a diagram showing a configuration of a rotating disk.

FIG. 3 is a diagram showing a state of a calibration light beam;

FIG. 4 is a diagram showing a positional relationship among a light source, a sample container, a rotating disk, and a spectroscopic analyzer in each measurement state.

FIG. 5 is a diagram showing a charge accumulation state;

FIG. 6 is a diagram showing another configuration example of the switching means.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Light source 6 Spectroscopic means 7 Array type light receiving element 30 Measurement part 71 Charge accumulation time adjusting means S sample

────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Susumu Morimoto 1-1-1, Hama, Amagasaki City, Hyogo Prefecture Inside Kubota Technology Development Laboratory Co., Ltd. (72) Inventor Shoka Shimizu 2-35 Jinmucho, Yao City, Osaka (56) References JP-A-57-128823 (JP, A) JP-A-62-188918 (JP, A) JP-A-62-137541 (JP, A) (JP, B2) (58) Fields surveyed (Int. Cl. ⁶ , DB name) G01N 21/00-21/01 G01N 21/17-21/61 JICST file (JOIS)

Claims (2)

(57) [Claims] A light source (1) for irradiating a measurement light beam to a measurement unit (30) from which a sample (S) to be measured can come and go.
Through the measuring unit (30) or the measuring unit (3
0) a spectroscopic means (6) for dispersing the measurement light flux reflected from the sample (S), and an array-type light receiving element (7) for receiving the separated measurement light flux. A spectrometer for performing component analysis, wherein wheat as the sample (S) is to be analyzed, and the charge accumulation time of the array-type light receiving element (7) is changeable. Charge accumulation time adjusting means (71) for increasing / decreasing control to keep the output from the array type light receiving element (7) within a predetermined output range set in advance ;
As the charge accumulation time, the standard accumulation time for dry wheat
Short term accumulation time for raw wheat and for dry wheat
The long accumulation time is set respectively, and the charge accumulation time is adjusted.
The means (71) sets the charge accumulation time to the three accumulation times.
A spectroscopic analyzer that performs switching control on either side . 2. The sample (S) to be measured can be moved out and back.
A light source (1) for irradiating a measuring light beam to a measuring unit (30)
Through the measuring unit (30) or the measuring unit (3
0) Spectral means for dispersing the measuring light beam reflected from
(6) and an array for receiving the split measurement light beam.
A light receiving element (7), and the sample (S)
A spectrometer for performing component analysis, comprising:
(S) as the object of analysis,
The charge accumulation time of the array type light receiving element (7) can be changed.
Controlling the charge accumulation time to increase or decrease
Output from the photodetector (7) is predetermined
A charge accumulation time adjusting means (71) within the range;
Said light source (1) is, have a maximum amount of light at a particular wavelength lambda _c
And, and the reduced amount of light at wavelengths away from certain wavelengths lambda _c
A small light source, the in the specific wavelength lambda _c Ares
Upper output setting value V _max and the lower limit output Lee light-receiving device (7)
The set value _Vmin is set in advance, and the charge accumulation time adjustment procedure is performed.
Stage (71), elements of the element corresponding to the specific wavelength lambda _c
Output said is larger than the upper limit output set value V _max
The charge accumulation time is controlled to be short, and the lower limit output set value V _min
If the charge accumulation time is controlled to be longer when smaller than
Is a spectroscopic analyzer.